Internal combustion engine



y 30, 1939- D. M. BERGES 2,160,324

INTERNAL COMBUST ION ENGINE Filed Dec. 15, 1937 INVENTOR.

Dona/d M. Be/yes Patented May 30. .1939

UNITED STATES PATENT OFFICE INTERNAL COMBUSTION ENGINE Donald M. Borges, Montclalr, N. J., assignor to Eclipse Aviation Corporation, East Orange, N. J., a corporation of New Jersey Application December 15, 1937, Serial No. 179,995

4 Claims. (Cl. 170135.6)

This invention relates to propeller control mechanism and more particularly to a speed control mechanism.

This invention finds particular use as a control mechanism for controllable pitch propellers and especially as a means for maintaining constant speed of the propeller and its driving mechanism by variations in the pitch of the propeller.

In connection with the operation of airplanes,

10 'the desirability of having means by which the speed of the engine, especially an internal combustion engine, could be maintained constant has long been known. Among the advantages to be obtained from maintaining a constant engine 15 speed might be mentioned the improvement in "take-ofl characteristics. There are, of course, many other conditions of flight in which the constant speed control mechanism is of particular advantage.

One of the objects of the present invention is to provide a practical propeller pitch control mechanism.

Another object of the invention is to provide speed responsive means for controlling the pitch 25 of a propeller, or of a plurality of propellers. In the latter phase of the invention, a feature is the provision of means for automatically correcting for any deviation, onthe part of one or more of the propellers, from a pre-selected speed, such 30 correcting means being adapted to vary the pitch of the deviating propeller or propellers sumcient- I 1y to bring such propeller or propellers back to the speed pre-selected to be the normal.

Other objects and advantages will be apparent from the attached specification and the accompanying drawing which illustrates what is now considered the preferred embodiment.

In the drawing:

Fig. 1 is a diagrammatic representation of an application of the invention to a single propeller and its driving engine;

Fig. 2 shows the electrical connections for a plurality of engine and propeller sets; and

Fig. 3 is a transverse view of the switch actuat- 45 ing mechanism of Fig. 1.

Reference characters Ill, II, I! and 13 point to the propellers 01' four associated engines l4, l5, l6 and I1, respecti'vely, each propeller having a pitch varying gear connecting therewith, in the 50 manner in which the gear 2| connects with the propeller III in Fig. 1, the corresponding pitch a varying mechanisms for the propellers I2 and I! being indicated in Fig. 2 at Ma, 2|b, and 2|c, respectively. The respective pitch varying 55 mechanisms may be as more fully illustrated and described in Patent No. 1,852,499 granted to J. R. Zipay on April 5, 1932, and the actuating means for the respective pitch varying mechanisms may be similar to that indicated in part at 46, 41 and 53 for the pitch varying mechanism 2|,it being understood that there will be similar actuating means individual to each of the other mechanisms 2|a, 2|b and 2|c. As shown the member 46 is shli'table along its axis in response to the. axial travel of the screw shaft 4| the operation. 10 of which will be more fully described hereinafter.

In addition to driving its propeller, each engine crankshaft drives one gear of a differential gear set, the drive from the engine It to its dif ierential gear set 22 being indicatedat 23 in Fig. l, and the other engines being similarly connected tosimilar differential gear sets not shown. Also driving a member of each differential gear set is a synchronous motor S1 for gear set 22, and S2,

S3 and S4 for the gear sets not shown. As shown go in Fig. 2, the motors S1, S2, S and S4 receive current from generator G which is in turn energized by mechanical connection with a constant speed motor P fed from a battery B or other suit able electricity source. Motor P may be set to 25 operate at the desired (preselected") speed by adjustment of rheostat ll.

fed from battery B, as shown, is a second series of motors 3|, 3|a, 3|b and 3|c, each of which is adapted to drive a gear train and screw shaft actuating mechanism, there being one such mechanism associated with each of the actuating means 46, 41 and 53 above described, and each of saiii gear trains and screw actuating mechanism being preferably similar to the one shown at 43 and 42 in association with the motor 3| of Fig.1. Each of the motors 3|, 3|a, 3|b and 3|c is normally de-energized, but eaohis adapted to rotate on closure of a switch mechanism operable by the differential action on its associated difier- 4o ential mechanism corresponding to the differential mechanism 22 which 'actuates motor control: ling switch mechanism 32 associated with the motor 3| in Fig. 1. As shown switch mechanism 32and the same will preferably be true of each 45 of the corresponding switch mechanisms 32 (a,

b, c) which are associated with the differential mechanisms for the other.enginesis movable in a rectilinear path within the limits established by the positioning of the complementary switch contacts 33 and 34, and engagement of the switch contact 32 with the contact 33 will result in energization of the windings of motor 3| which control and produce clockwise rotation of said motor, while engagement of the contact 32 with the conll tact 34 will produce energization of those windterclockw'ise rotation of said motor. Switch con tact 32 moves toward 33 or 34 only in the event of, and in response to, a difference in speed between shaft 23 and motor S1 (signifying a deviation of engine l4 from the pre-selected speed). Contacts 33 and 34, on the other hand, move only in response to axial travel of screw 4| to which they are integrated or otherwise positively connected. Screw 4| moves axially in response to rotation of nut 42, and rotation of nut 42 occurs only in response to rotation of motor 3| and the reduction train 43 connecting motor 3| with nut 42.

The means for producing rectilinear travel of the contact 32 in the event of and'in response to the difference in speed between shaft 23 and motor S1 is shown as including radially acting clutch elements 21 and 28 pivotally mounted on the cage 24 of the differential gear set and normally urged into torque transmitting engagement with the inner cylindrical surface of an externally threaded screw or helical cam 36 which meshes with a correspondingly helically grooved member 31 whose outer extension 38 is constrained by suitable means (as a rectilinear slot wall 39) into movement along a path which will carry the current conducting portion 32 thereof into ultimate engagement with either the contact 33 or the contact 34, to energize propeller control motor 3| for clockwise or counterclockwise rotation as the case may be. Thus the member 31 constitutes in efiect, the equivalent of an internally threaded nut adapted to travel in the plane of the axis of an actuating said nut in response to rotation of said screw, but as shown the member 31 does not completely encircle the member. 36, as in the case of an ordinary screw and nut, which is therefore in effect merely a sector or a segmental portion of said nut.

On the opposite end of screw 4| there is a collar 46 receiving one end of a yoke or bifurcated lever 41 fulcrumed at 48 and operatively attached to a linkage (as 53) in the manner in which linkage 53 is shown as connecting with of propeller l0, being one such linkage for each propeller shifting gear (2|, 2|a, 2|b, 2|c, Fig. 2), as above described.

From the for going it will be understood that the operation is:

Set speed of motor P at that desired. This sets speed of all synchronous motors,

either clockwise or counterclockwise (see Fig. 3) depending upon whether the speed of engine is greater or less than speed desired. Motion of differential cage 24 is transmitted through the clutch shoes 21 and 28 to the member 36 to produce rectilinear movement of the member 31 and the contact portion 32 carried thereby into ultimate engagement with either the contact 33 or the contact 34, to energize propeller control motor 3| for clockwise or counterclockwise robe. Such rotation moves contacts 33 and 34, and of theengine by its eflect By reason of the tation as the case may shaft 4| which carries also changes the speed upon members 53 and 2|.

movement thus imparted to contacts 33 and 34,-

as they are carried along with the screw 4|, there is the tendency to break the circuit between member 32 and either the member 33 or the member 34, depending upon which is engaged with 32 at the moment. This gives the necessary follow-up motion required for perfect synchronizing. During this follow-up motion cage 24 of differential 22, screw 36, member 31, conmaintain the engine at the desired speed.

Inasmuch as the speeds of all thesynchronous motors must be the same it follows that the engines to which they are connected will be in synchronism.

The purpose of the clutch connection between the cage 24 and the member 36 is to provide for an overload for release of the driving connection to the member 32 in the event that an unforeseen over-travel of the member 32 should result in a condition wherein further movement of said part 32 would be impossible because of a limitation upon the extent of possible axial travel of the screw shaft 4| which of course produces a corresponding limitation upon the extent to which the contacts 33 and 34 cuit having a pair of separately shiftable but inter-engageable contacts therein, means for circuit of the motor ing engine.

3. In combination with a plurality of variable speed internal combustion engines of the propeller driving type, means including 8. corresponding plurality of electric motors for varying the pitch of said propellers, to return the respective driving engines to a pre-selected speed, means for energizing each of said motors in response to departure of said engines from said preselected speed, said energizing means including a source of current, a circuit from said source, said circuit including said electric motor, speed deviation responsive means for closing said circuit. said speed deviation responsive means including a gear whose speed varies with variations in engine speed, a second gear whose speed remains constant, a diflerential connection therebetween, a circuit closing element movable with said differential connection, a co-operating circuit closing element in the path of movement of said first-named circuit closing element, and

means for moving said co-operating circuit closing element along said path in synchronism with the rotation of the motor whose circuit includes said two circuit-closing elements.

4. The combination with variable speed internal combustionengines of means including electric motors operable in response to deviation 01' said engines from a pre-selected speed, means responsive to operation of said motors to return said engines to said pre-selected speed, means for energizing said motors, said energizing means including a source of current and a circuit from said source, said circuit including said electric motor, speed deviation responsive means for closing said circuit, said speed deviation responsive means including a contact actuating member having an inner cylindrical surface, a plurality of clutch elements frictionally engageable with said inner cylindrical surface to transmit torque thereto up to a predetermined maximum capacity, andmeans including a diflerentlal gear carrying cage for driving said clutch elements whenever the speed 01 one of the differential gears deviates from the pre-selectedconstant speed of another of said gears.

DONALD M. BERGES. 

